title: Solid phase extraction of DNA from biological samples in a post-based, high surface area poly(methyl methacrylate) (PMMA) microdevice.
abstract: This work describes the performance of poly(methyl methacrylate) (PMMA) microfluidic DNA purification devices with embedded microfabricated posts, functionalized with chitosan. PMMA is attractive as a substrate for creating high surface area (SA) posts for DNA capture because X-ray lithography can be exploited for extremely reproducible fabrication of high SA structures. However, this advantage is offset by the delicate nature of the posts when attempting bonding to create a closed system, and by the challenge of functionalizing the PMMA surface with a group that invokes DNA binding. Methods are described for covalent functionalization of the post surfaces with chitosan that binds DNA in a pH-dependent manner, as well as for bonding methods that avoid damaging the underlying post structure. A number of geometric posts designs are explored, with the goal of identifying post structures that provide the requisite surface area without a concurrent rise in fluidic resistance that promotes device failure. Initial proof-of-principle is shown by recovery of prepurified human genomic DNA (hgDNA), with real-world utility illustrated by purifying hgDNA from whole blood and demonstrating it to be PCR-amplifiable.
authors.affiliation: Department of Chemistry, University of Virginia, McCormick Road, P.O. Box 400319, Charlottesville, Virginia 22904, USA.
authors.forename: Carmen R
authors.initials: CR
authors.lastname: Reedy
authors.forename: Carol W
authors.initials: CW
authors.lastname: Price
authors.forename: Jeff
authors.initials: J
authors.lastname: Sniegowski
authors.forename: Jerome P
authors.initials: JP
authors.lastname: Ferrance
authors.forename: Matthew
authors.initials: M
authors.lastname: Begley
authors.forename: James P
authors.initials: JP
authors.lastname: Landers
mesh_terms: D001774:Blood Chemical Analysis / Q000295:instrumentation / Q000379:methods; D048271:Chitosan / Q000737:chemistry; D004247:DNA / Q000097:blood / Q000302:isolation & purification*; D004867:Equipment Design; D006801:Humans; D006863:Hydrogen-Ion Concentration; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation* / Q000379:methods*; D019904:Polymethyl Methacrylate / Q000737:chemistry*; D052616:Solid Phase Extraction / Q000379:methods*; D013499:Surface Properties
chemical_list: D004247:DNA; D019904:Polymethyl Methacrylate; D048271:Chitosan